Emerson Spartz was 12 years old when he started Mugglenet.com, a Harry Potter fan site. Today, he is 20 and the site gets around 40 million visitors every month – not to mention that it is a strong commercial site. The Leaky Cauldron site is another HP fan site with a strong following. Who knows what will happen to these sites once book 7 is a distant memory, and movie seven has been released, but for now they’re keeping fans happy.